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Creating multiple scanners on System.in upsets the predictability of program behavior, especially when System.in has been re-directed.


Noncompliant Code Example

import java.util.Scanner;


public class InputLibrary\{

   public static int getInt()\{        System.out.println("Please enter an int:");        Scanner in = new Scanner(System.in);         return in.nextInt();     \}

   public static int getDouble()\{             System.out.println("Please enter a double:");             Scanner in = new Scanner(System.in);              return in.nextDouble();       \}

\}

Compliant Code Example

import java.util.Scanner;


public class InputLibrary{

   private static Scanner in = new Scanner(System.in);


   public static int getInt(){        System.out.println("Please enter an int:");        return in.nextInt();     }

   public static int getDouble(){        System.out.println("Please enter a double:");        return in.nextDouble();     }

}